Piston



TE Fri-Cel FREDERICK IIACHMANN, OF sT. LOUIS, MISSOURI, .'ASSIGNOR or ONE-HALE To HERMAN STIEEL, or ST. LOUIS, MISSOURI, ONE-SIXTEENTI'I To PHILIP E. MOODYl AND ONE-SIXTEENTH To OHAUNOEY R. WATSONBOTH OE DETROIT,

MICHIGAN, ONE-EIGHTH TO DAVID M. HUTCHINON, 0F FERGUSON,

MISSOURI,

AML ONE-SIXTEENTH To H. A. WRIGHT, or DETROIT; MICHIGAN.

PISTON.

To ail l1li/0m t may concern.'

Be it known that I', Fiuioiiuicic HACH- iuANN, a citizen of. the United States, andl resident ot the city ot St. 'Louis and State of Missouri, have invented certain new and useful Improvements in listons, of which the following is a specification containing a full, clear, and exact description, reference being had to accompanying drawings, forminra part thereof.

' y invention relates to 'new and useful improvements in pistons and especially re lates to pistons for internal combustion en: gines, the primary object of which is to ronstructa piston which will provide thorough and uniform lubrication and prevent the accumulation of carbon in and around the piston `rings thereby maintaining the full efficiency of the piston rings.

A further object is to construct a piston wherein the piston rings are uiaintained in fluid tight contact with the side walls of the piston ring grooves.

In the drawings:

Fig. 4 i's a cross-sectional view oi" the piston ring.

- Fig. 5 is an edge view oi the forcing ring with parts broken away and in section.

Fig. 6 is a' plan view oi' the oil distributinir ring made use ot'.

{eferring to the drawings, 7 indicates tliel cylinder-ot'. an Yordinary internal combustion engine. 8 indicates my improved piston which is provided. with piston ring channels'or grooves 9 .and l0, which are separated' by' the rib Oriangell. Formed 0n the rib or Hange l1, adjacent the groove 9 is an under-cut recess or channel l2, and formed on the opposite side of the said rib, adjacent the groove l0, is an iinder-ciit groove or recess 13. Both 'of these recesses Figure '1 is a vertical sectional vie'w o ,t' an .ring and .the sides of' the Specification of Letters Patent. Patented Spt 14, 1920` Application filed December 2 3, 1918.v Serial No. 268,016. y

, or grooves are formed alike and converge,

inwardly from the periphery of the rib 11. Mounted iu the groove i) is a piston ring 14, which may be oi any desired construevtion, and mounted in the groove l() is a similar ring lo. 16 and indicate what might be termed f loi-cmg rings, which are con-4 sti'iicted alike, and one located onjeaeh side of `the rib 11.and between the rib and the 18, which is made to fit in the 'flaring recess of tlie,rib. v

'.lhe forcing rings 1(3.and 17 are provided with a lap 19 of any desired and preferable construction. their respective recesses under compression and the expansive foi'cc'thereof will force the piston rings 14 vand 15 tightly against the sides of the pistou ring grooves so as to form fluid tight joints and prevent the accumulation of carbon around the piston rings.

In the present construction of pistons, it is well known that the accumulation of earbon around piston rings .destroys the -efiiciency ot' the rings and in all forms of piston rings, heretofore constructed, there has been no provision made for forming vafluid tight joint betweenthe sides of the piston grooves in which they :ire located.

vln my .improved construction, by virtue o i the employment of the beveled forcing ring, the sides ofjthe piston ring are forced against the -side Walls of the grooves, thus effecting a fluid tight` joint without interfer- .ing with the'e'xpansiveforce of thepistn '90 vbe readily observed by providing the fore-y rings proper, this being accomplishedas can These rings are placed in ing rings with beveled faces resting against an ini-.lined face of thev piston ring grooves in which the piston rings are seated.

In order to provide for thorough lubrica-.

tion of the piston, l form in the same, a cir-- cular channel 2() which extends from the edge of the --piston ring groove 10. This channel is cut at an angle as illustrated in Fig. 2 and below this channel I provide the piston with the usual oil ports 21.l

In order to thoroughly distribute the oil i which may accumulate in the oil channel wie kan oil channel with an oil for a thorough and uniform lubrication of.

Vof the piston ring grooves.

formed of brass or softer material than that out of which the cylinder or piston is formed. This ring in cross section is less than the width' of the groove or channel. 20, so as to permit the ring' to have a slight movement within the groove by the operation of the' piston.

As previously referred to, the essential feature of my improvement is to provide a fluid tight joint, between the sides of the piston rings and the grooves in which they are located, by means of a beveled faced forcingring, and to provide in the piston, distributing ring the piston. Y g

In assembling the parts of my improve ment, the forcing ring 16 and 17 are placed under compressionin their respective re' cesses and then the piston rings are seated in their respective piston ringy grooves and the tcndencyof the forcing rings to expand will force the piston rings against the sides When the pis- I employ an oil distributing ring 22.

ton rings have become Worn, they can be re laced Without changing the forcing rings.

aving fully described my invention, what I claim is:

In combination with a'piston having a pair of parallel piston ring grooves near its upper end, said piston ring grooves having their adjacent ends undercut, of a split ring triangular in cross section sprung into the undercut portion of each groove, a split ring rectangular in. cross section sprung ineach groove adjacent the triangular ring7 said last mentioned ring being larger in circumference than the triangular ring and the circumference of the piston, said triangular ring adapted to force the rectangular ring away from the undercut surface of the piston ring grooves y y In testimony whereof, I have signed my name to this specification, in presence of two subscribing witnesses.

FREDERICK HAOHMANN.

Vitnesses i EDWARD E. LONGAN,' ELIZABETH CARTALL. 

